Apoptosis modulation by activin A and follistatin in human endometrial stromal cells

Effects of Ulipristal Acetate on Reactive Oxygen Species and Proinflammatory Cytokine Release by Epithelial and Stromal Cells from Human Endometrium and Endometriosis

Endometriosis is a condition characterized by increased oxidative stress and chronic inflammation, which can be treated with progestins and other progesterone receptor ligands. However, some patients are refractory to this treatment and the reason is uncertain. Here we investigated the effects of the selective progesterone receptor modulator ulipristal acetate (UPA) on proliferation, reactive oxygen species (ROS), and proinflammatory cytokine production by endometriotic cells and endometrial cells from women with histologically proven endometriosis (n = 22) and endometriosis-free controls (n = 6). Epithelial and stromal cells were isolated and treated in triplicate for 24 h with 1 μM, 10 μM, or 100 μM UPA. Cells were tested for proliferation and ROS production, while cell supernatants were assayed for interleukin (IL)-6, C-C motif chemokine ligand 2 (CCL2), and tumor necrosis factor (TNF)-α concentrations. Proliferation, ROS production, and IL-6 and CCL2 secretion were increased in non-stimulated epithelial and stromal cells from endometriotic lesions compared to endometrial cells from endometriosis patients and controls. UPA induced a dose-dependent increase of cell proliferation only in endometriosis, while enhancing ROS production by all cell types evaluated. UPA reduced CCL2 production in controls but failed to do that in endometriosis, whereas TNF-α was undetectable. We conclude that treatment of endometriotic cells with UPA stimulated in vitro proliferation and ROS production and failed to revert the proinflammatory cytokine excess that characterized these cells, unravelling possible mechanisms of drug resistance in the treatment of endometriosis.

Quiescent Ovarian Cancer Cells Secrete Follistatin to Induce Chemotherapy Resistance in Surrounding Cells in Response to Chemotherapy

PURPOSE

We recently reported that the transcription factor NFATC4, in response to chemotherapy, drives cellular quiescence to increase ovarian cancer chemoresistance. The goal of this work was to better understand the mechanisms of NFATC4-driven ovarian cancer chemoresistance.

EXPERIMENTAL DESIGN

We used RNA sequencing to identify NFATC4-mediated differential gene expression. CRISPR-Cas9 and FST (follistatin)-neutralizing antibodies were used to assess impact of loss of FST function on cell proliferation and chemoresistance. ELISA was used to quantify FST induction in patient samples and in vitro in response to chemotherapy.

RESULTS

We found that NFATC4 upregulates FST mRNA and protein expression predominantly in quiescent cells and FST is further upregulated following chemotherapy treatment. FST acts in at least a paracrine manner to induce a p-ATF2-dependent quiescent phenotype and chemoresistance in non-quiescent cells. Consistent with this, CRISPR knockout (KO) of FST in ovarian cancer cells or antibody-mediated neutralization of FST sensitizes ovarian cancer cells to chemotherapy treatment. Similarly, CRISPR KO of FST in tumors increased chemotherapy-mediated tumor eradication in an otherwise chemotherapy-resistant tumor model. Suggesting a role for FST in chemoresistance in patients, FST protein in the abdominal fluid of patients with ovarian cancer significantly increases within 24 hours of chemotherapy exposure. FST levels decline to baseline levels in patients no longer receiving chemotherapy with no evidence of disease. Furthermore, elevated FST expression in patient tumors is correlated with poor progression-free, post-progression-free, and overall survival.

CONCLUSIONS

FST is a novel therapeutic target to improve ovarian cancer response to chemotherapy and potentially reduce recurrence rates.

Transcription factor SOX3 upregulated pro-apoptotic genes expression in human breast cancer

BACKGROUND

Sex-determining region Y-box 3 (SOX3) protein, a SOX transcriptions factors group, has been identified as a key regulator in several diseases, including cancer. Downregulation of transcriptions factors in invasive ductal carcinoma (IDC) can interfere in neoplasia development, increasing its aggressiveness. We investigated SOX3 protein expression and its correlation with apoptosis in the MDA-MB-231 cell line, as SOX3 and Pro-Caspase-3 immunoexpression in paraffin-embedded invasive ductal carcinoma tissue samples from patients (n = 27). Breast cancer cell line MDA-MD-231 transfected with pEF1-SOX3 + and pEF1-Empty vector followed by cytotoxicity assay (MTT), Annexin-V FITC PI for apoptosis percentage assessment by flow cytometry, qPCR for apoptotic-related gene expression, immunofluorescence, and immunohistochemistry to SOX3 immunolocalization in culture cells, and paraffin-embedded invasive ductal carcinoma tissue samples.

RESULTS

Apoptotic rate was higher in cells transfected with pEF1-SOX3 + (56%) than controls (10%). MDA-MB-231 transfected with pEF1-SOX3 + presented upregulation of pro-apoptotic mRNA from CASP3, CASP8, CASP9, and BAX genes, contrasting with downregulation antiapoptotic mRNA from BCL2, compared to non-transfected cells and cells transfected with pEF1-empty vector (p < 0.005). SOX3 protein nuclear expression was detected in 14% (4/27 cases) of ductal carcinoma cases, and pro-Caspase-3 expression was positive in 50% of the cases.

CONCLUSION

Data suggest that SOX3 transcription factor upregulates apoptosis in breast cancer cell line MDA-MB-231, and has a down nuclear expression in ductal carcinoma cases, and need to be investigated as a tumor suppressor protein, and its loss of expression and non-nuclear action turn the cells resistant to apoptosis. Further studies are necessary to understand how SOX3 protein regulates the promoter regions of genes involved in apoptosis.

Lifestyle and glycemic health 5 years postpartum in obese and non-obese high diabetes risk women

AIM

Women with prior gestational diabetes (GDM) are at increased diabetes risk. This study aimed to assess whether lifestyle is associated with glycemic health of high-risk women 5 years postpartum, taking into account the pre-pregnancy BMI.

METHODS

The RADIEL study enrolled before or in early pregnancy 720 women with pre-pregnancy BMI ≥ 30 kg/m2 and/or prior GDM. The follow-up visit 5 years postpartum included questionnaires and measurements of anthropometrics, blood pressure, and physical activity (PA) as well as analyses of glucose metabolism, lipids, and inflammatory markers. We measured body composition (Inbody) and calculated a Healthy Food Intake Index (HFII) from Food Frequency Questionnaires (FFQ). ArmBand measured PA, sedentary time, and sleep. To take into account the diverse risk groups of GDM, we divided the women based on pre-pregnancy BMI over/under 30 kg/m2.

RESULTS

Altogether 348 women attended the follow-up. The obese and non-obese women showed similar prevalence of glycemic abnormalities, 13% and 19% (p = 0.139). PA levels were higher among the non-obese women (p < 0.05), except for step count, and their HFII was higher compared to the obese women (p = 0.033). After adjusting for age, education, and GDM history, PA and HFII were associated with glycemic health only among obese women. When both lifestyle factors were in the same model, only PA remained significant. PA associated with other markers of metabolic health also among the non-obese women, excluding HbA1c.

CONCLUSION

Lifestyle 5 years postpartum was associated with better glycemic health only among the obese high-risk women. PA, however, is essential for the metabolic health of all high-risk women.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, http://www.clinicaltrials.com , NCT01698385.

Activin A overexpression promotes rat follicular development through SCF-kit-mediated cell signals

We explored the possible signaling pathway by which activin A induces oocyte maturation. Inhba-overexpressing lentivirus vectors were constructed and transfected into primary granulosa cells in vitro and ovary tissues in vivo in rats. The granulosa cell growth curve was drawn, and antibodies for phospho-Smad2, phospho-Erk5, phospho-Nur77, and stem cell factor (SCF) were prepared for western blot analysis. Protein expression of SCF and C-kit in the rat ovaries was detected by immunohistochemical staining. The rate of granulosa cell proliferation was higher in the Inhba gene overexpression group (INH) than in the control groups (CON group and GFP group) in vitro. Protein expression of SCF and C-kit was higher in the INH group than in the other two groups. phospho-Smad2, phospho-ERK5, P-nur77, and SCF proteins showed positive expression in rat ovarian granulosa cells in each group and were obviously increased in the INH group. Activin A overexpression may promote rat granulosa cell proliferation through Smad2/ERK5/nur77 signaling pathways, and rat granulosa cells overexpressing activin A in vitro showed increased levels of SCF and c-kit proteins.

LncRNA MALAT1 inhibits apoptosis of endometrial stromal cells through miR-126-5p-CREB1 axis by activating PI3K-AKT pathway

Endometriosis is a common, chronic and painful disease in women, whose pathogenesis remains not entirely clear. Long non-coding RNA (lncRNA) MALAT1 participates in the development of endometriosis. This study further investigated the regulation of MALAT1-miR-126-5p-CREB1 axis in the pathological process of endometriosis. MALAT1, miR-126-5p, and CREB1 levels in human endometrial stromal cells (HESCs) were detected by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Protein levels were determined by Western blotting. Cell viability and apoptosis was assessed by MTT assay and annexin V-FITC staining, respectively. The interactivity between miR-126-5p and MALAT1 (or CREB1) was assessed by dual luciferase reporter system. Knockdown of MALAT1 or CREB1 restrained proliferation and induced apoptosis as confirmed by upregulating cleaved caspase-3 and Bax, and down-regulating Bcl-2 in HESCs, while inhibition of miR-126-5p presented the opposite results. Moreover, silencing of MALAT1 triggered apoptosis of HESCs via targeting miR-126-5p. In addition, miR-126-5p directly regulated CREB1 expression via binding to its 3' non-coding region. Finally, miR-126-5p inhibitor-mediated apoptosis inhibition was restrained by CREB1 silencing via inactivation of PI3K-AKT pathway in HESCs. Taken together, our study firstly demonstrates that MALAT1 regulates apoptosis of HESCs through miR-126-5p/CREB1 axis mediated PI3K/AKT pathway. Our findings explained the pathogenesis of endometriosis and offered promising therapeutic option for endometriosis.

Involvement of activin signal pathway in cyclic apoptosis of the oviductal isthmic epithelium in cows

Activin (ACV) A induces various cellular functions via activin receptor type 2 (ACVR2A/2B)-activin receptor-like kinase (ALK) 4 -Smad 2/3 pathway. Although the production of ACVA is indicated in bovine oviducts, its role on the oviduct is unclear. Oviductal isthmus needs to change its function rapidly at peri-fertilization, however, the mechanism is unknown. This study was aimed to clarify the role of ACVA in the morphological changes of oviductal isthmus in cows. First, mRNA expressions of INHBA (ACVA component) and its receptors (ALK4, ACVR2A and ACVR2B) in the isthmic tissues were examined throughout the estrous cycle. INHBA was the highest, however, ACVR2A was the lowest on the day of ovulation, suggesting reduced ACV signal transduction in the isthmus just after ovulation. Proteins of ACVRs and Smad2/3 were clearly detected in the cultured epithelial cells. It is known that ACVA regulates cellular apoptosis. Our data showed that the number of cleaved caspase-3-positive epithelial cells was largest at 2-3 days after ovulation in the isthmus. Interestingly, our study demonstrated that follistatin (ACV/TGFB/BMP inhibitor) significantly decreased the BCL2/BAX ratio in the cultured isthmic epithelial cells. To clarify which ALK pathway is involved in the regulation of BCL2/BAX ratio, the effects of SB431542 (ACV signaling (ALK4) and TGFB signaling (ALK5) inhibitor), SB525334 (ALK5 inhibitor) and LDN193189 (BMP signaling (ALK2/3) inhibitor) were investigated in the next study. The results showed that only SB431542 significantly decreased BCL2/BAX and the others had no effects. These results suggest that decreased ACVA-ACVR2A-ALK4 signal at the post-ovulation induces cyclic apoptosis of isthmic epithelial cells in bovine oviducts.

Follistatin Protects Against Glomerular Mesangial Cell Apoptosis and Oxidative Stress to Ameliorate Chronic Kidney Disease

Aims: Interventions to inhibit oxidative stress and apoptosis, important pathogenic contributors toward the progression of chronic kidney disease (CKD), are not well established. Here, we investigated the role of a transforming growth factor beta (TGFβ) superfamily neutralizing protein, follistatin (FST), in the regulation of apoptosis and oxidative stress in glomerular mesangial cells (MCs) and in the progression of CKD. Results: The endoplasmic reticulum (ER) stress inducer thapsigargin (Tg), known to cause MC apoptosis, led to a post-translational increase in the expression of FST. Recombinant FST protected, whereas FST downregulation augmented, Tg-induced apoptosis without affecting Ca²⁺ release or ER stress induction. Although activins are the primary ligands neutralized by FST, their inhibition with neutralizing antibodies did not affect Tg-induced apoptosis. Instead, FST protected against Tg-induced apoptosis through neutralization of reactive oxygen species (ROS) independently of its ability to neutralize activins. Importantly, administration of FST to mice with CKD protected against renal cell apoptosis and oxidative stress. This was associated with improved kidney function, reduced albuminuria, and attenuation of fibrosis. Innovation and Conclusion: Independent of its activin neutralizing ability, FST protected against Tg-induced apoptosis through neutralization of ROS and consequent suppression of oxidative stress, seen both in vitro and in vivo. Importantly, FST also ameliorated fibrosis and improved kidney function in CKD. FST is, thus, a novel potential therapeutic agent for delaying the progression of CKD. Antioxid. Redox Signal. 31, 551-571.

Activin A in Mammalian Physiology

Activins are dimeric glycoproteins belonging to the transforming growth factor beta superfamily and resulting from the assembly of two beta subunits, which may also be combined with alpha subunits to form inhibins. Activins were discovered in 1986 following the isolation of inhibins from porcine follicular fluid, and were characterized as ovarian hormones that stimulate follicle stimulating hormone (FSH) release by the pituitary gland. In particular, activin A was shown to be the isoform of greater physiological importance in humans. The current understanding of activin A surpasses the reproductive system and allows its classification as a hormone, a growth factor, and a cytokine. In more than 30 yr of intense research, activin A was localized in female and male reproductive organs but also in other organs and systems as diverse as the brain, liver, lung, bone, and gut. Moreover, its roles include embryonic differentiation, trophoblast invasion of the uterine wall in early pregnancy, and fetal/neonate brain protection in hypoxic conditions. It is now recognized that activin A overexpression may be either cytostatic or mitogenic, depending on the cell type, with important implications for tumor biology. Activin A also regulates bone formation and regeneration, enhances joint inflammation in rheumatoid arthritis, and triggers pathogenic mechanisms in the respiratory system. In this 30-yr review, we analyze the evidence for physiological roles of activin A and the potential use of activin agonists and antagonists as therapeutic agents.